What are the three most daunting problems facing middle-class American families today? Health, home and college education.

On Thursday, President Obama and Education Secretary Arne Duncan rolled out a plan to get college costs under control.

But there is little confidence that the measures outlined will do much for students’ families.

The most alarming fact. according to the White House: “Average tuition and fees at public four-year colleges have more than tripled in the past three decades.”

During that same period, according to Census Bureau data, that growth far exceeds gains in family income. Today’s median family income, according to a Sentier Research report issued last week, sits at $52,098, 4.4 percent below the 2009 level.

In 2009, the average private four-year college cost, including tuition, room and board, books and fees was $39,028. Today it stands at $43,289.

But these private schools have endowments — totaling more than $406 billion, according to the National Association of College and University Business Officers.

These nonprofit “ivy hedge funds” take in nearly $30 billion a year in donations. Harvard’s endowment has more than $31 billion, and those of Yale, Stanford and Princeton have almost $20 billion each.

Why not take every “not for profit” college with an endowment of more than $100 million — of which there are 405 — and say, “In order to keep your tax-exempt status, you have to reduce tuition by 5.6 percent, which is the average annual net return for these funds over the last 10 years”?

Under these new ground rules, colleges can invest, but they would have to pass along their gains to students in the form of a tuition reduction. This way students would benefit, not the fund managers.

College endowments and donations are fine — so long as the schools that receive them don’t treat them like deposits into their own private globe-trotting investment funds.

In other words, so long as college officials remember why they chose that world as a career.